webpack.config.js

var path = require('path');
var webpack = require('webpack');
var BundleTracker = require('webpack-bundle-tracker');
var ExtractTextPlugin = require("extract-text-webpack-plugin");

module.exports = {
	entry: [
		'./app/index.js'
	], 

	devtool: 'eval',
	debug: true,

	output: {
		path: path.resolve('./public/bundle/'),
		filename: 'main.js',
		publicPath: 'http://localhost:3000/public/bundle/'
	},

	plugins: [
		new BundleTracker({filename: './webpack-stats.json'}),
		new ExtractTextPlugin("style.css", {
			allChunks: true
		})
	],

	module: {
		loaders: [
			{ test: /\.css$/, exclude: /node_modules/, loader: ExtractTextPlugin.extract('style-loader', 'css-loader') },
		    { test: /\.json$/, loader: 'json-loader' },
			{ test: /\.jsx$/, loaders: ['jsx-loader'], include: path.join(__dirname, 'app') },
			{ test: /\.es6$/, exclude: /node_modules/, loader: 'babel-loader?stage=0&optional=runtime'},
			{ test: /\.js$/, exclude: /node_modules/, loader: 'babel-loader?stage=0&optional=runtime'},
			{ test: /\.scss$/, exclude: /node_modules/, loader: ExtractTextPlugin.extract('style-loader', 'css-loader!sass-loader') }
		]
	},
}

webpack.watch.js

var path = require('path');
var config = require("./webpack.config.js");
var Webpack = require("webpack");
var ExtractTextPlugin = require("extract-text-webpack-plugin");

var port = process.env.WEBPACK_PORT || 3000;
var host = process.env.HOST || 'localhost';

config.entry.unshift(
    "webpack-dev-server/client?http://" + host + ":" + port,
    "webpack/hot/only-dev-server"	// only prevents reload on syntax errors
);

config.plugins = [
	new Webpack.HotModuleReplacementPlugin(),
	new Webpack.NoErrorsPlugin(), // don't reload if there is an error
	new ExtractTextPlugin("style.css", {
		allChunks: true
	})
];

config.module.loaders = [
	{ test: /\.css$/, exclude: /node_modules/, loader: ExtractTextPlugin.extract('style-loader', 'css-loader') },
  { test: /\.json$/, loader: 'json-loader' },
	{ test: /\.jsx$/, loaders: ['react-hot', 'babel-loader'], include: path.join(__dirname, 'app') },
	{ test: /\.es6$/, exclude: /node_modules/, loader: 'babel-loader?stage=0&optional=runtime'},
	{ test: /\.js$/, exclude: /node_modules/, loader: 'babel-loader?stage=0&optional=runtime'},
	{ test: /\.scss$/, exclude: /node_modules/, loader: ExtractTextPlugin.extract('style', 'css!sass') }
];

config.devServer = {
	// publicPath:  'bundle',
	publicPath:  config.output.publicPath,
    filename: 'main.js',
    contentBase: './public',
    hot:         true,
    // Make connection between webpack-dev-server and its runtime set inline: true
    inline:      true,
    lazy:        false,
    quiet:       true,
    noInfo:      true,
    headers:     {"Access-Control-Allow-Origin": "*"},
    stats:       {colors: true},

    // webpack-dev-server will serve built/bundled static files from host:port
    host:        "0.0.0.0",
    port:        port
};

module.exports = config;